Sacramento's Discovery Museum explains asteroid traffic

SACRAMENTO, CA - How does a meteoroid explode in Russia's atmosphere causing property damage and injuries to more than a thousand people, and scientists not see it coming?

Experts at the Challenger Learning Center at the Discovery Museum explain to kids Friday morning that dark, fast moving rocks pass by the earth all the time.

"It's black and it's in black space," said Bernta Bechler, flight specialist at the Challenger Learning Center. "It's just lucky that someone saw a shadow pass over a point in the sky and they thought 'that's a little weird, let's figure out what it is.'"

Within hours of the Russian meteoroid explosion, a bigger asteroid sped past earth in one of the closest encounters in recent history. This asteroid, named "2012 DA14", is the size of a baseball field and traveling eight times faster than a bullet. Several dozen school children came to the museum Friday to learn that rock wouldn't turn into a sky explosion.

"They let us hold a rock that was kinda like it," said 9-year-old Cheyenne Turner, who added the rock didn't seem scary at all.

"They told me not to be scared because it's not going to hit the earth, but I kinda wanted it to because it'll be cool if it cracked some continents," said 9-year-old Emir Mlivic.

The most common form of meteorite to hit earth is a solid piece of metal, but experts think the one in Russia was probably porous and trapped enough hot air to explode before hitting the ground. Perhaps the most reassuring news about the bigger asteroid that just passed us, was that it never even came close to home.

"17,200 miles is the closest it will get to us," Bechler said. "So imagine being in your car and driving that far. It's 4 days to get across the US and that's 3,000 miles."